International Journal of Hydrogen Energy, Vol.45, No.11, 6538-6548, 2020
Co-Ni alloy supported on CeO2 as a bimetallic catalyst for dry reforming of methane
Dry reforming of methane (DRM) is an effective route to convert two major greenhouse gas (CH4 and CO2) to syngas (H-2 and CO). Herein, in this work, monometallic Ni/CeO2 and a series of bimetallic Co-Ni/CeO2 catalysts with Co/Ni ratios between 0 and 1.0 have been tested for DRM process at 600-850 degrees C, atmospheric pressure and a CH4/CO2 ratio of 1. The catalysts were characterized by X-ray diffraction, hydrogen-temperature programmed reduction, CO2-Temperature programmed desorption, X-ray photoelectron spectroscopy, and thermogravimetric analysis. The catalyst with a Co/Ni ratio of 0.8 (labeled as 0.8 Co -Ni/CeO2) exhibited the highest catalytic activity (CH4 and CO2 initial conversion for 80% and 85% at 800 degrees C, respectively) and the highest stability (less carbon deposition after 600min). This improved activity can be attributed to the Co-Ni alloy, which formed after reduction. Its weak chemisorption with hydrogen results in inhibition of reverse water gas shift reaction. In addition, Co-promoted the adsorption of surface oxygen enhances carbon removal, making it more stable. (C) 2020 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.